Bevel erotkaeiob fob bafters



I O'Ct. 13, 1931. L D JANNELL 1,827,014

BEVEL PROTRACTOR FOR RAFTERS Filed April 2'7, 1928 Patent-ed oct. 13, 1931 LESLIE D. JANNELL, QESHEEBOEN, MASSACHUSETTS f vREVEL ERo'rEacToE ron vEAFTEES s .appliationv inea Aprn 27,

The yobject of this invention is to provide a protractor whereby a carpenter may quickly and accurately mark a hip rafter and a jack rafter to gui-de a saw informing a onefaced or single beveled end on a jack rafter, and a two-faced or double beveled Vsshaped end on a hip rafter.

I attain this ,and other related objects,

f by the improved construction hereinafter den v f1@ scribed and claimed. f Of the accompanying'drawings forming a part of this specification, j FigureV 1 is a side view', showingv a 'protract- "or embodying the invention, in a folded inoperative condition. j

Figure 2 isa side View, showing the `protractor in an operative condititon, the .pro tractor arm being partially projected from the holder. j

Figure 3 is an enlarged fragmentary sectional View, on line 3'-3 of'Figure 1, portions of the'holder and armA being broken away. Fig-ure 4 is a section online t-4; of Fig ure 2. y

Figure 5is a fragmentary side View similar to a portion of Figure 21, showing a different position of the protractor arm, a portion of the holder being broken away.

Figure 6 shows a portion' of a jack rafter andthe protractor applied thereto.

Figure 7 shows a portion of a hip rafter and the protractorapplied thereto.

Figurey 8 shows a portion of the jack raftel` anc 1 1 Figure 9 a portion ofthe hip rafterrafter the ends of said rafters-have been beveled.

Figure 1Q shows in perspective, a portion of thefframing of' a hip roof, which includes hip rafters and jack rafters. 'Y

The same'reference' characters indicate the same partsin all of the figures. .Y a designates the plate, b hip rafters, c jack rafters, and e the ridge pole of a hip roof, f designates a central raft-er extending from the'V plate a. to the ridgepole, between two groups of jack rafters c. rlhe upperend of each hip rafter I) is provided with two beveled faces g, forming a V-shaped end. The upper end of each jack rafter is'p'rovded with a 1.928. Serial No. 273,230.

single beveled face It, all in accordance with. comm-on practice. e

My improved-protractor is intended and adapted only to enable a carpenter to forni suitable marks on the edge face of the rafters' '5 b land c, to guide the saw'which forms ythe faces g g on a hipir'after, and the face 7L on a jack rafter, the transverse bevel of .said faces crosswise of the rafter being" determined by said marks. The yvertical vb evel from thel upper to the lower edge of the rafter may be determined by marks formed, 'as usual, by the aid of another instrument, such as a carpenterssquare.

The protractor includes any oblong holder" Vil ` and a protractor4 arm pivoted to one end of the holder, the ylatter being flat-sid`ed and adapted to be laid onan edge faceof arafter,

- as indicated by Figures 6 and 7. The holder is provided with spaced apart laterallypro-.. jecting stops 13 and 14E, arranged to-bear on a side face ofthe rafter and with a longitudinal ledge face 15,'obliquely arranged relativeto thel stops, the arrangement being'suchthat when the stops bear on the side face of th'eefg f raf'ter, the edge face 15 extends diagonally entirely across the edge face of the rafter, as shown by Figures 6 and 7.

17 designates the protractor arm, which is oblong, and is pivoted at one endto one end of.' the holder, and adapted yto swing in a plane parallel with the holder. The armis pro vided with a marker-guiding longitudinal Y straight edge 18, adapted to extend diagonallyl entirely across the edge face'of the rafter, at..` e5 an angle determined by a swinging adjustment of the arm relative to the holder.

The protractor includesmeans for locking the arm 17 to the holder in any position` to which the arm is adjustable, so vthat thev straight edge 18 may be adjusted at various angles, as indicated by Figures 2 and 5.

I will now describe indetail the preferred construction of` the holder, theprotractor yarm, and 'the arm-locking means. 9:3

The holder comprises a pair of flat oblong plates 20, and studs 21. and22 (shown respectively by Figures 3 and 4),. rigidly connecting said plates 'at their opposite ends, j and spacing themapart. The studlis'a 100 til) pivot on which the protractor arm 17 is adapted to swing between the holder plates, and is provided with extensions projecting from opposite sides of the holder, each eXtension constituting a lateral stop 13, above described, there being two stops 13, as shown by Figure 8.

The stud 22 is a locking lever pivot or fulcrum on which is fulcrumed a locking lever of bell-crank form, including a shorter arm 23, and a longer arm 24e.

The protractor arm 17 is provided at its free end with an arcuate transverse edge 25, concentric with the pivot stud 21. The holder plates 2O project from the edge 25, and are provided with arcuate edges 2G., eccentric to the pivot stud Q1. The longer arm 24 of the locking lever extends lengthwise of the eccentric edges 26, and is provided with a forked slide 27, having a gripping face 28, bearing on the edges as shown by Figure 3.

The arrangement is such that when the slide 27 is in the dotted line position, shown by Figure 5, the locking lever is loose and ino aerative, and when the slide is moved to the full line position, its gripping face 28 coopcrates with the eccentric edges 26 in pressing the shorter arm 23 of the locking lever against the arcuate edge 25 of the protractor arm, and thereby locking the protractor arm to the holder.

The above described lateral stops 14 are ears integral with the holder plates 20 and bent outwardly therefrom, as shown by Figures 3 and 4.

It will now be seen that the protractor is adapted to be applied to a rafter with either side outward. Vllhe straight edge 18 of the protractor arm may face to the left, as shown by Figure 6, and guide a marker in forming a mark indicating the cut which forms thel beveled end face 7L (Figure 8).

In marking a hip rafter the protractor is first applied with one side outward, while the straight edge is guiding a marker in forming a mark indicating the ont which forms one of the beveled end faces g (Figure 9), and with the other side outward while the straight edge is guiding a marker in forming a mark indicating the cnt which forms the other beveled end face g.

The arcuate edge 25 of the protractor arm is provided with a projection 30, constituting a stop member adapted to limit the swinging movements of the arm, said member abutting the shorter arm 23 of the lever, when the protractor arm is swung to the position shown by Figure 2, and a stop member 31 on the longer lever arm when the protractor arm is swung to the position shown by Figure l.

The sides of the protractor arm 17 may be inscribed in any suitable way, to enable a carpenter to adjust the straight edge 18 to the angle required by the length and rise of the rafter.

In this instance, the swinging end portion of the protractor arm is provided on each sic-.e with a row of serially numbered graduations 3Q, which are numbered as 3, ll, 5, 6, 7, etc., each number denoting the rise in inches of the rafters b, c and f to each foot of run of the plate (z, the run being half the length of the plate, and the graduations being so spaced that when any one of them is brought into registry with the edge face 15 of the holder, the edge 18 of the protractor arm will be in the proper relation to the stops 13 and 14 to give the proper angle for the side-cuts of the jack, hip, and valley rafters associated with the particular graduation brought into registry. One side of the protractor arm is further provided with a row of graduations 33, in cooperative relation to the graduations 32, any particular graduation 33 in line with the edge face 15 of the holder in a given setting for angle of side cut corresponding to the length of hip rafters Z; per foot of run.

rlfhe other side of the protractor arm is shown in Figure 7, with a row of graduations 33a', similar to the graduations 33, in cooperative relation to a row of graduations 32a, similar to the row 32, the graduations 33a in line with an opposite edge face 15a of the holder in a given setting for angle of sidecut, corresponding to the length of the central rafter f and of the jack rafters c per unit of run.

The holder plates 2O and protractor arm are preferably of the approximately triangula form shown by Figures 1, 2, 6 and 7, the longitudinal edges of each diverging from the end where the pivot stud 21 is located, and the length of the transverse arcuate edges being considerably shorter than the diverging edges. The instrument thus formed may be proportioned to be conJ veniently carried in a pocket.

l claim: n

l. A bevel protractor for rafters, comprising a flat-sided oblong holder, having spaced apart laterally projecting stops arranged to bear on a side face of a rafter and locate the holder on an edge face thereof, with one of its longitudinal edges eXtei/iding diagonally across said edge face, an oblong prctractor arm pivoted at one end to the holder to swing in a plane parallel therewith, and having a marker-guiding longitudinal straight edge, adapted to extend diagonally across the edge face of the rafter at an angle determined by a swinging adjustment of the arm, and means for locking the protractor arm to the holder in any position to which said arm is adjustable, the arrangement being such that the edge face of a jack raf'ter may bepr vided with a marl; to guide a saw in forming a one-faced beveled end thereon,

and the edge face of a hip rafter may be provided with marks to guide a saw in forming a two-faced or V-shaped beveled end.

2. A bevel protractor as specified by claim l, the holder comprising a pair ot flat oblongb plates, and studs rigidly connecting sai plates at their opposite ends and spacing the plates apart, one of the studs being a pivot on which the protractor arm is adapted to swing between the plates, the stops projecting from opposite sides of the holder, so that the protractor may be applied to a ratter with either side outward.

3. A bevel protractor as specified by claim l, the holder comprising a pair of fiat oblong plates, and studs rigidly connecting said plates at their opposite ends and spacing the plates apart, one of the studs being a pivot on which the protractor arm is adapted to swing between the plates, and the other stud being a each foot of run, said graduations being so arrangedA that when any one of them is brought into registry with the straight edge of the holder, the edge of the protractor arm will signature. Y

LESLIE D. JANNELL.

lockinglever pivot, the holder plates having transverse arcuate edges which are eccentric to the protractor arm pivot, the pro-V tractor arm having a transverse arcuateedge concentic with said pivot, the protractor armk locking means comprising a locking lever fulcrumed on the lever pivot and including a shorter arm arranged to bear on the arcuate edge of the protractor arm, and a longer arm extending lengthwise of the' eccentric edges of the holder plates, and a shoey slidable on the longer arm and having a gripping face adapted to cooperate with said eccentric edges in pressing the shorter arm against the concentric edge of the protractor arm, and thereby locking the latter to the holder in any position to which it is movable.

et. A bevel protractor for rafters, comprising a comparatively thin holder having a straight edge and internally recessed inwardly from said edge to receive and enclose a protractor arm, fixed stops on said holder arranged to bear on a side face of a rafter, a

swingable protractor arm having a straight edge swingably secured to said holder and movable into and out of the recess of said holder, there'being graduations on the protractor arm denoting the riser of the rafter to each foot of run, said graduations being so arranged that when any one of them is brought into registry with the straight edge of the holder, the straight edge of the protractor arm will be in proper relation to the stops to give the proper angle for the side.- cuts of the rafters.

5. A bevel protractor for rafters, comprising a comparatively thin holder having a straight edge and internallyrecessedinwardlyfrom said edge to receivevand enclosefa protractor arm, fixed stops on said holder arranged to bear on a side face. of a rafter, a swingable protractor arm having a straight edge swingably secured to said holder and movable into and out of the recess of said holder, there being graduations on the protractor arm denoting the rise of the raiter to f 

